# CVE-2011-5133: Cross-site scripting in n/a

> An unspecified vulnerability in MyBB allows attackers to inject malicious scripts via unparsed user avatars in the buddy list, potentially compromising user sessions.

- **Severity:** Critical 10.0 (`AV:N/AC:L/Au:N/C:C/I:C/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 30 Aug 2012
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-xxrm-wh3c-cfmr

## What is CVE-2011-5133?

CVE-2011-5133 is a critical cross-site scripting vulnerability in Mybb Mybb, published on 30 Aug 2012. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Unspecified vulnerability in MyBB before 1.6.5 has unknown impact and attack vectors, related to an "unparsed user avatar in the buddy list."

## Which versions are affected by CVE-2011-5133?

It affects 1 product.


Products: Mybb Mybb.

## How do I fix CVE-2011-5133?

No fix has been published for CVE-2011-5133 yet. Limit exposure of the affected software until one is available.

## Is CVE-2011-5133 being exploited?

There is no known exploitation of CVE-2011-5133 in the wild and no public exploit code.

## Other vulnerabilities in Mybb Mybb

- [CVE-2011-10018](https://insights.sbomify.com/CVE-2011-10018/): myBB 1.6.4 Backdoor Arbitrary Command Execution (critical 10.0)
- [CVE-2015-2786](https://insights.sbomify.com/CVE-2015-2786/): Information disclosure in n/a (critical 10.0)
- [CVE-2006-0218](https://insights.sbomify.com/CVE-2006-0218/): SQL injection in n/a (critical 10.0)
- [CVE-2020-22612](https://insights.sbomify.com/CVE-2020-22612/): Code injection in n/a (critical 9.8)
- [CVE-2017-16780](https://insights.sbomify.com/CVE-2017-16780/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2011-5133 and fix it if it is affected.

What it is: CVE-2011-5133 is a critical cross-site scripting vulnerability in Mybb Mybb, published on 30 Aug 2012. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2011-5133 in the wild and no public exploit code.

Affected product: Mybb Mybb. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2011-5133/ (Markdown: https://insights.sbomify.com/CVE-2011-5133/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2011-5133
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2011-5133
- OSV: https://osv.dev/vulnerability/CVE-2011-5133

---
From sbomify Insights: https://insights.sbomify.com/CVE-2011-5133/
Summaries are generated and may contain mistakes; the official description above is the record.